But don’t rush for your binoculars just yet. According to former Springwatch presenter Bill Oddie, the bird of prey is becoming more and more common in inner London, drawn to the large population of pigeons.

Mr Oddie, from Hampstead, said: “It’s not rare any more, 10 years ago it would have been quite an unusual sight.

“It’s quite a common phenomenon to see them nesting in sky scrapers around the world, which act as artificial cliffs – where you would normally find them.

“But it’s great to see them because some years ago they were getting rarer and rarer. Those numbers have improved no end and they are absolutely spectacular in flight – the fastest animal in the world during its vertical dive.”

The bird is believed to be eight-month-old Gus, born on June 6 last year on the roof of the Tate Modern.